With advancements in technology, means of transmitting data has changed from use of a physical medium, such as mail, to the use of telecommunications. Unfortunately, the use of telecommunications for the transmission of data has introduced concerns as to security of the transmitted data.
Encryption is an example of technology utilized to provide a more secure method of transmitting data from a first point to a second point. In addition, the secure transmission provided by encryption is intended to prevent a third party from eavesdropping on the transmission. Unfortunately, classical encryption techniques are vulnerable to interception and decryption by third parties.
To alleviate this problem quantum encryption has been proposed. Quantum Key Distribution (QKD) is an advanced technology capable of fast, reliable, and unconditionally secure (in terms of computational power) quantum key distribution over a large distance. A QKD system typically provides an apparatus utilized for secure key exchange between two distant parties that are connected via a means of communication, such as an optical cable. Specifically, in QKD, a key is established between a sender (“Alice”) and a receiver (“Bob”) by using weak (e.g., 0.1 photon, on average) optical signals transmitted over a “quantum channel.” The security of the key distribution is based on the quantum mechanical principal that any measurement of a quantum system in an unknown state will modify its state. As a consequence, an eavesdropper (“Eve”) that attempts to intercept or otherwise measure the quantum signal will inherently introduce errors into the transmitted signals, thereby revealing her presence.
A typical QKD system contains a quantum layer, comprising a single photon counter, that is utilized to prepare and deliver the quantum signal from Alice to Bob, a data acquisition system (e.g., a computer with an input/output (I/O) card), a bi-directional classical data communication channel, and at both Alice and Bob, data processing logic utilized to distill the hidden key from raw data. Software protocols are also an important portion of the QKD system, and are utilized to run the QKD system and perform different actions, such as, authentication, sifting, error correction, and privacy amplification. The QKD system may also contain different types of classical encryption hardware and software that are known to those having ordinary skill in the art. The hidden key is typically produced by a random number generator (RNG), which may be provided as a portion of Alice.
The transmission of the Quantum key requires reduced power so as to allow for transmission of single photon pulses or signals. Alternatively, the transmission of data packets over a public discussion layer (e.g., Ethernet) requires large amounts of power. Large amounts of power, resulting in the transmission of thousands of photons at a time, may result in Raman and Rayleigh scattering, thereby negatively affecting the single photon pulses. Due to the different requirements of the Quantum Key distribution path and the public discussion layer, it is difficult, if not impossible, to transmit the Quantum Key and data over the public discussion layer, both on the same optical fiber. Instead, a single fiber is typically dedicated for the public discussion layer, while a second fiber is used for Quantum key distribution. Alternatively, the fiber distance is shortened so that input power may be reduced and so the scattering power transfer ratio is lower due to the shorter fiber distance.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.